The present invention relates to a system for monitoring the performance of oil wells system includes a beam deformation sensor, a current intensity loading sensor and a beam angle sensor.
In the petroleum industry, there are many thousands of production oil wells, many in remote locations. Forty percent of these wells work with a beam type pumping unit having a beam displaceable through an angular range, a sucker rod connected to the beam and an electric driving motor for causing angular movement of the beam through a rotating member and a connecting member between the rotating member and the displaceable beam. FIG. 1 illustrates a typical beam type pumping unit of this type.
Normal wear and tear, as well as the nature of the fluid being pumped and/or abnormal pumping conditions, can cause such problems as worn-out pumps, broken sucker rods, split tubing, malfunctioning vacuum pumps, and stuck pump valves - all of which interfere with and interrupt normal pumping operations. Maintenance of these wells and their equipment demands many man-hours. Despite continuous maintenance programs, well imperfections and failures are often detected too late by maintenance crews and their supervisory personnel resulting in large repair expenses.
As mentioned above, beam pumping units are typical. In order to detect possible malfunctions in the well pumping system, two variables are measured-the load on the displaceable beam and the displacement of the beam. These two measured variables are used to obtain a diagram known as a dynagraphical chart or dynagraph. From these charts, performance of the well is monitored.
Over the years, different pieces of equipment and different types of systems have been developed to detect problems in the pumping units of these oil wells. For example, some wells are equipped with a force sensor placed directly at the polished rod of the beam pumping unit and a second sensor which measures the displacement of the beam. From the measurements recorded by these sensors, it is possible to obtain the desired dynagraphs.
Some wells are also equipped with sensors for monitoring the performance of the electrical motors used in the well. These sensors typically consist of a loading coil designed for use with an electrical motor so that the loading coil voltage is proportional to the current circulating through the motor feeder cables.
The principal deficiency of these sensors has been an inability to provide maintenance personnel with an accurate picture of the condition of the well equipment. The electrical motor sensors are further deficient in that they lack a system which permits normalization of different currents into instrumentation standard outputs.
Accordingly, it is an object of the present invention to provide an improved system for monitoring well performance.
It is a further object of the present invention to provide an improved current intensity loading sensor to be incorporated into said system.
It is still a further object of the present invention to provide an improved current intensity loading sensor as above having means to permit normalization of the output to industry standard outputs.
It is yet another object of the present invention to provide an improved beam deformation sensor to be incorporated into the well monitoring system.
Still another object of the present invention is to provide an improved beam angle sensor to be incorporated into the well monitoring system.
These and other objects and advantages of the present invention will become more apparent from the following description and drawings wherein like reference numerals depict like elements.